The binding of macromolecules (e.g. antibodies) and macromolecular assemblies (e.g. viruses) to cell surfaces is critical to a host of biologically and medically important processes. The current research proposal attempts to disclose the mechanistic details of such binding via the study of simple and controllable models involving the interaction of amphiphilic polymers with vesicular systems. The polymers are both negatively and positively charged, and they differ in their charge density and degree of polymerization. The vesicles with which they interact differ in curvature (small, large, and giant) and in their content of charged lipid. Association of the polymers with the vesicles will induce structural rearrangement, including lateral lipid segregation ("domains"), pore formation, and flip-flop all of which will be examined as a function of polymer and vesicle composition. Polymer-vesicle interaction has also been shown to affect transport of an antitumor drug, doxorubicin, an effect that will be further studied owing to its importance in the drug delivery arena. Finally, complexation of the polymers with DNA will be examined with respect to the association with, and transport through, the vesicular bilayers.